A transformer is used to light a lamp rated 40w, 240v from a 400v A.C supply. Calculate:
1 answer:
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Answer:
1 x 10¹⁷
Explanation:
Given data:
Radius of the earth = 6000km
Radius of an atom = 60pm
Now, how many orders is the radius of the earth larger than an atom
Solution:
To solve this problem, let us express both quantity as the same unit;
1000m = 1km
6000km = 6000 x 10³m = 6 x 10⁶m
60pm;
1 x 10⁻¹²m = 1pm
60pm = 60 x 1 x 10⁻¹²m = 6 x 10⁻¹¹m
Now;
The order: = 1 x 10¹⁷
The elastic potential energy of a spring is given by
where k is the spring's constant and x is the displacement with respect to the relaxed position of the spring.
The work done by the spring is the negative of the potential energy difference between the final and initial condition of the spring:
In our problem, initially the spring is uncompressed, so
. Therefore, the work done by the spring when it is compressed until 
is
And this value is actually negative, because the box is responsible for the spring's compression, so the work is done by the box.
where k is the spring's constant and x is the displacement with respect to the relaxed position of the spring.
The work done by the spring is the negative of the potential energy difference between the final and initial condition of the spring:
In our problem, initially the spring is uncompressed, so
And this value is actually negative, because the box is responsible for the spring's compression, so the work is done by the box.